Sanding machine



F. HARRIS SANDING MACHINE May 27, 1952 4 Sheets-Sheet 1 Filed Sept. 27. 1948 INVENTOR Fox- Is?! filarrz's ATTORNEYS F. HARRIS SANDING MACHINE May 27, 1952 4 Sheets-Sheet 2 Filed Sept. 27. 1948 ATTORN EYS F. HARRIS SANDING MACHINE May 27, 1952 4 Sheets-Sheet 5 Filed Sept. 27. 1948 INVENTOR Foz-is f J'Carris p w 2 MN BWM'IIH W Nw R.

ATTORNEYS May 27, 1952 HARRIS 2,598,053

SANDING MACHINE Filed Sept. 27, 1948 4 Sheets-Sheet 4 m QL L T K INVENTOR. \353 Fol-is 2 Harris BY m mui,

Patented May 27, 1952 izUNITED sm'ras parent O'FFICE 1 SANDING MAGHENE Eorist Harris, Merced, Calif., assignor to The Brunswick-Balke-Collender Company, Chicago,

Ill'., a' corporation oi. Delaware "-'A'p;i1ieation September 27, 1948, Serial N5. 51387 Y 11 Claims.

This invention has for an object the provision of anauto'matic'sanding machine for bowling fia'lleysi there being a' novel arrangement to ac- "dm'pl'ish' effective guiding of the machine" along analle'yf 'andth'machine being arranged to automatically reverse at the ends of the alley.

Another object of the'invention is to provide a sanding machine,"for "bowling alleys, which in- "cludes a novel leveling mechanism; such mechanism being operative, automatically, to cause the "sandingunit -by re'a'son' of weight transfer-to cut"fasterbn'ielatively high areas, whereby the -surfacerdf anal-ley issandedto a-common transverseleveland'withinjvery close limits. A r bj pf the invention is to provide asandingamachine, for; bowling alleys, which is arranged to take 'advantage'of the lateral thrust, "orside draft, imposed on;the machine by the transversely-disposed-endless sanding belt, to r lise e e'elem s-qf said m in to remain -atalltimes-in machine guiding engagement with --the upstanding longitudinal'shoulder of one gutter of thealley beirigsanded. M additional object of the invention is to proyide the machine with a novel," endless belt sanding unit; said unitibeingiarrang'edfor easy and convenient removaland replacement of the sanding belt by the'operator on ajobn I e I It is also an object of theIpreSent'inVention to prbtiqe, deeming-mac i e 'for' bowling alleys, 7 whic eludes novel driving means for the power 4 actuate frjnchanisms' on the machine. 7 A furtherbbject of theinvention is to provide a'fpracticalj, "rliablefand accurate automatic n in hicl'i willbe'exc'eeding'lyeffective for the purpose 1? wh ch it 15 9 8 1 9 e. .b i ti ar ia ii hfifiF' of such 'structure and'relative" arrangement of parts "a will' fully appe ar by a 'pei'i'isalof the following specification and claims.

* In the drawings: r a H v Fig 1 is a top plan view of 'themachine; the electric wiringbeing-om-itt'ed' for clarity.

- 1g; 2' is an' eiflaiged frontend elevation'of the i e-W igi 3 isan "enlargedf fragmentary-elevation, tly H Y onj-ofion'eof the spring-urged but "ractible' endless-sanding belt tightening asgeaeress-sectipn online' as ow t mamportioner the autoa'chine for bowlingalleys, and'one comprises arectangular traction frame, indicated generally-at I supported; at its front end; and on 'opposite sides, by'driven floor engaging wheels 2 fixed on opposite ends of a cross shaft 3. ;At its opposite or rear end the traction frame 'I is supported by transverselyspaced casters 4;. e A

The above wheel-supported traction frame is pivotally secured, intermediateits ends and on opposite sides-, as at 5, totherearends of a pair of forwardly projecting connection arms 6.- Ahead of the traction frame 1 the connecti'on arms B'eX- tend-through, and are securedinconnection with, a rectangular frame I of an endless belt, sanding un t di ted e ne a yt The rectangular frame 1' of the sanding unit 8 is of a width, transversely-Z of the direction of travel, substantially that of the floor 9- of a bowling alley, while the traction frame I is somewhat narrower, as shown 7 e y V The machine is reversibly'driven, as follows: A reversible motor [6 is mounted on the, traction frame 1 and drives the crqss shaft 3 through the medium of a speed-reducingdrive assembly i i. "The motor 5 Q is of the type which includes a reversing lever 12,-and thearrangement for controlling this lever is hereinafter described; it suffices at this point to state that thereversible motor It acts toadvance the machine from one end of a bowling alley to the other end, and is then automatically reversed 'to' return the machine to its starting'position. I

The endless belt, sanding unit 8 comprises a "transversely extending, endless sanding belt I3 carried, at opposite'ends; on end rollers l4 supported by 'end' shafts l5 mounted in connection with the frame 1, as follows:

Oneof th'e'end' shafts IE'has a fixedmount,

"including endheads'h'i on rigidarms l7.

rods t'outv'iardlxtogether with 'the-head's l 8 and l thecorrespondingend shaft l 5;-w'h'e'reby toinaintain the endless sanding belt 53 under the-desired working tension.

For the purpose of facilitating the removal and replacement of the endless sanding belt I3, the end heads It can be drawn or adjusted inwardly, to loosen such belt, in the following manner:

A pull link 22 pivotally connects between each end head I8 and a radial lever 23 journaled on the corresponding side of the frame I by means of a stub shaft 24 having a nut 25 thereon. By applying a wrench to each nut 25 and rotating the same so as to swing the lever 23 and pull link 22 from the normal full-line position of Fig. 3 to the dotted-line position in said figure, the desired result is accomplished.

To further expedite removal and replacement of the endless sanding belt I3, the sanding unit 8 is elevated above the floor 9 of the alley by the following device:

A hand lever 26 is pivotally mounted on the rear end of the traction frame I at one side thereof, and a link 27 pivotally connects between the lever 25 and a cam assembly 28 mounted between the front end of the traction frame I and corresponding points on the connection arms 6. By swinging the hand lever 26 rearwardly, the link 2'! causes the cam assembly 28 to push upwardly on the connection arms 6, raising the sanding unit 8 clear of the floor a short distance, but which clearance is sumcient to permit of the convenient removal and replacement of the sanding belt l3.

The endless sanding belt I3 is driven, in the direction indicated by the arrow in Fig. 4, by the following arrangement:

An electric motor 29 is mounted on the traction frame I, and actuates a speed reducing drive assembly 36, which in turn actuates a universal drive shaft 3i which extends longitudinally along one side of the traction frame I and connects in drivin relation to the corresponding end shaft IS. The end roller I I on said driven end shaft I5 has a friction grip surface 32, while the surface of the opposite end roller is relatively smooth.

The motor 29 also drives a suction fan 33 having a pick-up hose 34 which leads from a dust collector 35 at the end of the sanding unit 8 toward which the bottom run of the belt I 3 travels. The suction fan 33 discharges the dust into a bag 36.

When the machine is in operation with the endless sanding belt is driven in the direction indicated by the arrow in Fig. 4, the lower run of said belt, acting transversely on the floor 9 of the bowling alley, imparts side draft or lateral thrust to the machine in the same direction as indicated by said arrow. This lateral thrust is taken b advantage of to maintain the machine in straight-line travel along the alley, in the following manner:

Transverse guide arms 3! are secured to the sleeves 2i) and extend lengthwise thereof to a point beyond the corresponding end of the sanding unit 8, and at their outer ends such guide arms 31 carry guide rollers 38 which bear against the upstanding longitudinal shoulder 39 of the adjacent gutter til. Thus, as the machine advances, the side draft or lateral thrust imparted thereto by the sanding belt I3 maintains the rollers 38 positively in contact with the shoulder 39, whereby the machine must, of necessity, travel in a straight line; i. e. parallel to said shoulder 39. The guide arms 37 are adjustably connected, at their inner ends, to the sleeves 2B, whereby the machine may be initially positioned correctly.

The sanding unit 8 is of a length transversely of the direction of travel of the machine such that the end portions of the sanding belt I3 overhang the gutters 40.

The following leveling mechanism is employed in the machine:

A secondary frame 4 I of rigid rectangular construction, is disposed above the frame I of the sanding unit 8; being supported from the latter by corner legs 42. The forward pair of these legs merely rest on the frame I, while the rearward pair are hinged, as at 43, whereby the secondary frame 4!, and the parts mounted thereon, may be swung upwardly and rearwardly when a sanding belt is being removed and replaced.

At opposite ends thereof the secondary frame II carries cross shafts 44, each having a roller 45 thereon, and such rollers 45 are adapted to be simultaneously rotated in the same direction, but reversibly, from a reversible motor 46 mounted centrally on the secondary frame 4!. The drive arrangement is as follows:

The reversible motor 48 is coupled to a fluid drive unit 41, and the latter in turn drives an endless chain and sprocket unit 48 which leads to one of the cross shafts 44. Another endless chain and sprocket unit 49 connects between said cross shafts. Thus, when the motor 46 turns in one direction or the other, there is a corresponding and simultaneous rotation of the rollers 45.

A very heavy steel roller or cylinder 59, disposed horizontally and extending lengthwise of the direction of travel of the machine, is normally in a position centrally between the ends of the sanding unit I; such roller 50 being supported, at its opposite ends, in tracks 5I which extend transversely of said direction of travel of the machine; 1. e. lengthwise of the sanding unit I. The tracks 5I incline upwardly in opposite directions from their center points whereby the roller 50 tends at all times to return by gravity to its normal and central position, as in dotted lines in Fig. 1 and as in full lines in Fig. 4.

A pair of spaced tapes 52 is anchored, as at 53, to each end of the secondary frame 4 I, thence extends inwardly about the roller 50, and returns to the corresponding roller 45; winding about, and being secured to, the latter. With this arrangement of tapes, and upon reversible drive of the rollers 45, the steel roller 50 is pulled up the inclined tracks 5i to the right or left from its central position, dependent upon the direction of rotation. The purpose of this shifting of the steel roller 50 laterally of the direction of travel of the machine is to shift its effective weight transversely with respect to the floor 9 of the alley being sanded. The rectangular frame I of the sanding unit 8 includes, at the bottom, a platen 54, preferably resiliently surfaced on the under side; such platen being of a substantial area and operative to maintain the lower run of the sanding belt I3 fiat.

As the machine travels along the alley, the steel roller 58 remains in its normal central position as long as the alley is transversely level. However, if a low spot or area is encountered to one side or the other of the longitudinal center of the alley, the steel roller 50 is automatically rolled or shifted in an opposite direction, whereby to impose its weight above the relatively higher area on the other side of the alley so that the sanding belt I3 is caused to cut faster on said relatively higher area. The result is that the machine cuts away such relatively higher area 55 including a central contact 56 and end'con- 'tacts The switch 55 responds to any variance from true transverse level of the floor fi-of'the alley, to actuate theabove described leveling mechanism; the circuit arrangement 'between switch 55 and reversible motor 4% being--herein-'- after described.

The sandingmachine, when in use; is first positioned at one end of thealley, and the guide rollers 38 properly adjusted in abutment with'the adjacent gutter shoulder 39. Thereaffterfthe" sanding unit 8 is placed in operation by starting the motor 23; the actuating circuit for the'latter being indicated at'58 in'Fig. 6. Such circuit includes a manualswitch 59, and the circuit is energized frcm an electric power supply circuit With the sanding unit 8 in operation,the"reversible drive motor lll is placed in operation'in a direction to cause the machine to advance along the alley, in sanding relation, from said one end thereof." The actuating circuit for the reversible motor it is indicated in Fig. 6 at-6i; such motor, as previously described, being of a type which is reversed by movement of a lever I2 on said motor. This reversing lever is actuated in one direction or the other by means of a twoway electro-mechanical relay'fiZ to which are connected a-pair of reversing circuits, indicated at63 and 6d. The reversing circuit- 63 includes a normally open'contactor 65, while the reversing circuit 6 3 includes a'n'ormally open contactor'66.

The contactor 65 is mounted, in forwardlyfacing relatiomon the upper end of a post'tfl which upstands from therear'of the traction frame I.

The contactor 66 is mounted in rearwardly facing relation on a lateral arm 68 which projects from one side of said traction frame I.

After the machine has advanced along the alley from one end thereofand reaches the opposite end, the contactortfi 'strike's'the normally I raised pin setting frame or cage aboveth'e'for Ward end of the alley. When this occurs the circuit 63 is closed; reversing the relay" 82, and the latter in turn swings the lever H2 in a direction to reverse the drive motor 1 l8. the machine stops-its forward travel and isthen retracted along-'the alley, bythethen r'e'versed motor 'ifl, to its starting position.

When the machine reaches its starting posi- The result is that I tion, thecontactorlitengages a heavy block 69 disposed in predetermined position. Upon clos- "ing of the contactor '66, the circuit't i again' reverses the electromechanical 'relay'EZ so that the leverl2 i's swung'to a position wherein the motor fi drives the machine forwardly. At this point,

'theicycle of operation 'may be terminated by opening a manualswitchlii'in theactuating "circuit 6!, or the machine may-be'permitted to again advance andretra'ct along the alley "until the same is completely sanded.

As the machine travels back and ioirthalong ..thei' alley; the: hereinb'eforedescribed leveling rlmechan'ismiunctions automatically to sandrela- 'tively: high L areas downto -the level of trans- 2 2verse1y disposed; relativelylow areas the controlf of the leveling "mechanism being byf-the' ransw versely elongated merccry tube switch 55, whose ircuiting" 'arrang'ement',-with respect to the fever- 1 I he;r'e 'ver'sible motor iii manna-cred, as shown in*l5ig-.- 63* in a'reversingcircuit, indicated g'enerally at '7 I"; which 'rever'sin'g' circuitincludes one lead 1-2 connected tothe-centrak contact-56 of the switch 55, and which -contact 56 isalways in electrical engagement with the mercury in' the j tubep Additionally; the reversing" circuit 1| ineludes reversing-leads 'l3- and 14exten'dingbe- "tween the motor lfi-"andcorresponding cries of the end contacts -filf-the" latter being-normally ""open; 1. efinormally-clearofthenierCury in the 'tube of'saids witch 55. p

If the machine as it travelsfrides onto an area "Wliich is relativelylowonone side of the center "lineofthe alley, the corresponding endolf' the tube of "switch fifi will also lower, whereupon the mercury" closes 'with'th'e adjacent oo'ntact 5'l.

This closesthe'reversihg circuit H through either 1 a' directionto'shift the" steel roller-58 'fromits normal central position to alateral position above the side of the 'alley opposite suchrelatively .low

-- area, for the 'purposehereinbefore' described';' towit automatic sanding "down of the relatively higher area to" the level" of the relatively 10w "area. Should itbe 'necessarfvto do so,the' reversing circuit for the'levling mechanism'a'ctuating -m0t0r-6 may be'opened by a manuar'switch' T5 interposed therein.

I The-steel roller 56 remains in such laterally shifted position as long as thereversing circuit H is closed and the motor 46 running; the fluid Y drive-unit Al-permitting slippage in the drive after-the; motor has shifted the roller 59 to its lateral position. 7 g

-As=soon as the part of the alley which initially had differential transverse level is sandedto a common level, the switch 'returns to its open positionythemotor 66 ceases to run; and the steel -roller '50 returns -by gravity to its normal central position. -Itwill thus be obvious that the leveling mechanism'of the machine functionsautomatically,effectively, and accurately, whenever a transversely untrue areaof a bowling -="-aliey isen'counteredby the traveling sanding machine. The'connectionarms 6 are detachable from the 'trac'tion frame I at the pivots 5; the-hose-M is --'detachablymounted; and the universal" drive I "shaft-B t is separable; all-'for' the purpose of permittingsaid 'ti'act-ion' frame'and the parts mounted thereon to' beseparated from the re- 1 m'airider of the machine for transport.

"The s'anding'ma'chine; being wholly automatic,

provides for the practicaLefi'ective', and economical sanding of bowling alleys; requiring a minimum of attendance while in: operation, and yet 'perrorming n-le operation with greater" accuracy than can otherwiseoe accomplished.

" Frorii the foregoing" description it will bereadily 'se'en thatthere has been produced such adevice as substantially fulfills the objects of the inven- 'tion, I as 'set "-forth herein.

=While this specification sets forth in detail the p'resent'andpreferred construction of the device,

still in practicesuchrleviations from such: detail may be re orted to as do not form a departure rwin- 131163;

"irit oi? the invention, ,1 asdefined by Having thus-"described the inventiongthe following is claimed as new and useful, and upon which Letters Patent are desired:

1. A bowling alley sanding machine comprising a frame, means adapted to move the frame lengthwise on an alley, a driven sanding unit mounted on the frame for alley engagement, a weight member mounted in connection with the frame for shifting motion transversely of the alley, and means operative, in response to transversely unlevel portions of the alley traversed by the machine, to shift said weight member toward and to a point above the high side, whereby to then impose a greater weight on the part of the sanding unit engaging said high Side.

2. A bowling alley sanding machine comprising a frame, means adapted to move the frame lengthwise on an alley, a driven sanding unit mounted on the frame for alley engagement, a weight member mounted in connection with the frame for shifting motion transversely of the alley, and means operative, in response to transversely unlevel portions of the alley traversed by the machine, to shift said weight member toward and to a point above the high side, whereby then impose a greater weight on the part of the sanding unit engaging said high side; said last named means including a reversible electric motor, a reversing circuit for the motor, and a switch in the circuit responsive to transverse unlevel of the machine when on such portions of the alley.

3. A machine, as in claim 2, in which the switch is a mercury tube type, elongated transversely of the direction of travel and mounted in connection with the frame.

4. A bowling alley sanding machine comprising a frame, means adapted to move the frame lengthwise on an alley, a driven sanding unit mounted on the frame for alley engagement, a weight member mounted in connection with the frame for shifting motion transversely of the alley, the weight member being normally disposed substantially centrally with respect to the lengthwise path of the machine, mechanism operative to move the weight member laterally to one side or the other of its normal position, and means operative, in response to transversely unlevel portions of the alley traversed by the machine, to automatically cause said mechanism to move the weight member laterally to the side corresponding to the high side of the unlevel alley portion being traversed.

5. A machine, as in claim 4, in which the weight member is a relatively heavy metal roller disposed with its axis extending in the direction of travel; there being transverse tracks on the frame supporting the roller at opposite ends.

6. A machine, as in claim 5, in which each track inclines upward in opposite direction from an intermediate point; said mechanism, when inactive, releasing the roller to return by gravity to its normal position.

7. A bowling alley sanding machine comprising a frame, means adapted to move the frame lengthwise on an alley, a driven sanding unit mounted on the frame for alley engagement from side to side thereof, a pair of matching transverse tracks mounted in connection with the frame in spaced relation in the direction of travel, each track inclining upward in opposite directions from a central point, a relatively heavy metal roller extending between the tracks and supported thereby, the roller normally being at said central point by gravity, mechanism operative to move the weight member laterally to one side or the other of its normal position, and

means operative, in response to transversely unlevel portions of the alley traversed by the machine, to automatically cause said mechanism to move the weight member laterally to the side corresponding to the high side of the unlevel alley portion being traversed.

8. A bowling alley sanding machine comprising a frame, means adapted to move the frame lengthwise on an alley, a driven sanding unit mounted on the frame for alley engagement from side to side thereof, a pair of matching transverse tracks mounted in connection with the frame in spaced relation in the direction of travel, each track inclining upward in opposite directions from a central point, a relatively heavy metal roller extending between the tracks and supported thereby, the roller normally being at said central point by gravity, mechanism operative to move the weight member laterally to one side or the other of its normal position, and means operative, in response to transversely unlevel portions of the alley traversed by the machine, to automatically cause said mechanism to move the weight member laterally to the side corresponding to the high side of the unlevel alley portion being traversed; said mechanism including transverse tapes anchored at one end to points on the frame at opposite sides of the weight roller and thence extending laterall inwardly and about said weight roller, power driven rollers mounted on the frame on opposite sides of the weight roller, the tapes connecting at their other ends to the power driven rollers, and a power drive operative to simultaneously rotate the power driven rollers in one direction or the other.

9. A bowling alley sanding machine adapted to move lengthwise on an alley, comprising a power driven sanding unit operative to engage and sand the alley from side to side thereof, a transversely shiftable Weight on the machine, means responsive to transversely unlevel portions of the alley traversed by the machine operative to automatically shift the weight toward the high side of such portion as lowered, reversible power means to move the machine, and means operative to automatically reverse said power means upon predetermined travel of the machine on an alley.

10. A bowling alley sanding machine, comprising: a frame; motor means adapted to move the frame lengthwise on an alley; a driven sanding unit coupled with the frame to ride on the alley and to be carried along with movement of the frame over the alley, said sanding unit having a transversely moving sanding belt for alley engagement, a platen positioned above said belt and resting thereon for maintaining the belt in engagement with the alley, said sanding unit being free to tilt transversely to follow the transverse contour of the alley; means carried by the machine for exerting a greater pressure on one side of the sanding unit relative to the other side; and automatic means mounted on the machine in fixed relation to the platen and operative in response to tilting of' the sanding unit on unlevel portions of the alley traversed by the machine to operate the pressure exerting means whereby to exert a greater pressure on the high side of the sanding unit relative to the other side.

11. A bowling alley sanding machine, comprising: a frame; motor means adapted to move the frame lengthwise on an alley; a driven sanding unit coupled with the frame to ride on 9 the alley and to be carried along with movement of the frame over the alley, said sanding unit having a transversely moving sanding belt for alley engagement, a platen positioned above said belt and resting thereon for maintaining the belt in engagement with the alley, said sanding unit being free to tilt transversely to follow the transverse contour of the alley and having its weight distributed substantially uniformly over the alley when the platen and alley are level; means carried by the machine for shifting the effective weight of the sanding unit toward one side thereof relative to the other side; and automatic means mounted on the machine in fixed relation to the platen and operative in response to tilting of the sandin unit on unlevel portions of the alley traversed by the machine to operate the weight shifting means to shift the effective weight of the sandin unit toward the high side of the platen.

FORIST HARRIS.

10 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,857,564 Olson May 10, 1932 1,877,031 Olson Sept. 13, 1932 1,905,296 Lundquist Apr. 25, 1933 2,093,779 Mapps Sept. 21, 1937 2,106,535 Pattison et al Jan. 25, 1938 2,205,566 Kollner June 25, 1940 2,265,354 Dahl Dec. 9, 1941 2,272,273 Parker Feb. 10, 1942 2,342,267 Gofi Feb. 22, 1944 2,480,325 HadWiger Aug. 30, 1949 

